All of the rivers in the United States are not monitored closely for pollution levels.
The statement in the question is False
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Explanation:</u></h3>
Not all rivers in the United States are closely monitored for their pollution levels. There are volunteers who take responsibility of checking water bodies such as lakes, rivers, streams etc. They take the next step required after finding a water body contaminated.
But to say that all the rivers receive the same amount of attention and action is incorrect. To ensure that all the rivers are clean and pollution free, it would require a lot of man power in the said department which would collect the water samples from all these rivers and send it to labs for checking the pollution level of the particular river. It can be said that the rivers which are situated beside an industrial site, close to a town, will be the priority for checking pollution levels as it would directly cause harm to a small set of population if the toxicity is at an increased level.
Answer: D. The object would have an acceleration of 6 m/s/s to the right.
Explanation:
I got it right on USA test prep
Answer a) is incorrect as sound does not travel in a vacuum.
Answer:
option A
Explanation:
given,
distance between two masses is doubled
new distance, r' = 3 r
using gravitational force equation
............(1)
new gravitational force
now from the given condition
now, from equation (1)
now, the change in gravitational force factor is equal to 
Hence, the correct answer is option A
Answer:
Remains the same
Explanation:
The speed of waves of higher and lower frequency both will be same.
the speed of sound in a medium is constant and independent of it's frequency. Moreover, when the frequency changes wavelength changes accordingly, such that their product remains constant.
we know that
υ×λ = constant = velocity
υ= frequency
λ= wavelength.
